Cardiac surgeons currently employ a variety of techniques to accomplish valvular reconstruction within the hearts of patients. For example, cryo-preserved allografts, bovine jugular vein grafts, porcine valves, and autologous pericardium have all been used in such valvular reconstruction procedures. However, these known techniques all suffer from several major limitations. More specifically, cryo-preserved allografts are prone to calcification and failure over time, and the high costs and low availability of allografts limit the utility of allografts in developing countries. These grafts also increase the likelihood that the anti-human antibodies of a patient will react with, and ultimately reject, a future heart transplant due to prior antigen exposure. Jugular vein grafts, although widely available, can only be provided in a narrow range of sizes, and the jugular vein grafts are prone to undesired calcification and aneurysmal dilatation. Similarly, porcine valves calcify over time, leading to a significant decrease in the integrity of the valves, particularly in children. Autologous pericardium has been used with short-term success; however, the procedures employing autologous pericardium are typically complicated and time-consuming, and are, therefore, unsuited for use in most countries. Moreover, autologous pericardium calcifies over time, and a patient's own pericardium cannot be used as a replacement valve material when the patient has had previous heart surgeries.
Additionally, known valve conduits that are employed in valvular reconstruction procedures are typically formed from multiple pieces, such as, for example, a graft portion and a valve portion. Thus, before these valve conduits can be used, the valve portion must be properly secured within the graft portion. This limitation adds significant complexity and time to the overall procedure, and the two-part structure of the resulting valve conduits can contribute to failure of the device.
Furthermore, at a fundamental level, known valve conduits are used to replace a defective valve rather than to regenerate a native valve. Thus, following implantation, these valve conduits are incapable of achieving formation of a physiologically and anatomically correct replacement valve.
In developing countries, cost and supply constraints limit the widespread use of alternative conduits for valvular reconstruction operations. Thus, there is a need for a readily available, low-cost valve replacement material that can easily be used during surgical procedures in developing countries.
Accordingly, there is a need in the art for a heart valve conduit that, upon implantation within the heart of a subject, is configured to promote regeneration of a replacement heart valve, including leaflets and sinus portions that are identical or substantially identical to the leaflets and sinus portions of a native valve. There is a further need for a unitary, implantable heart valve conduit that distally integrates into a native artery such that, over time, the synthetic material of the heart valve conduit is undetectable. There is still a further need for a sterile, acellular, and low-cost heart valve conduit that can be quickly and efficiently constructed using readily available materials or that is pre-constructed for rapid implantation.